Clear pending jobs

For performance reasons, some actions in the database are delayed, and are managed by the job queue. Those jobs are stored in database and contain parameters with information about actions it should perform.
It's strongly recommended to run those pending jobs before upgrading the wiki, to avoid them failing in case the parameter specification of those jobs change on the new version.
Use runJobs.php to run all pending jobs and clear the queue before performing the upgrade.

Once done, make this new folder the published folder on the web server, or rename the old installation directory and then rename the new one to match the old name.

Git verwenden

If using Git, export the files into a clean location, and then copy the old customized files into the new location as described in the previous section.

If you are upgrading to MediaWiki 1.25 or later, you will also need to install some external PHP libraries using Composer or a provided collection maintained for the Wikimedia wiki farm. More details on installing and updating external libraries can be found in the Git download documentation.

Using patch

A small patch file is usually made available for a minor version upgrade. Manually download and extract the patch file from the dumps site or follow the directions with wget below. Patches are incremental, you can not skip a version.

cd to your main MediaWiki directory (the one with LocalSettings.php).

Download the patch file and gunzip it.

Use patch -p1 --dry-run to check what will be changed (e.g., patch -p1 --dry-run -i mediawiki-x.xx.x.patch)

If all is well, run patch again without --dry-run.

Check your Special:Version and you should see the new version number in place.

MediaWiki 1.24 changes the paths of core skin files. After upgrading to this version, you should ensure that the old files CologneBlue.php, Modern.php, MonoBook.php and Vector.php directly in the skins/ directory are no longer present. See Manual:Skin autodiscovery for details.

Erweiterungen aktualisieren

Certain extensions have been updated in order to work with the new version of MediaWiki. Be sure to upgrade to the latest versions of such extensions. You might need to perform manual updates to custom extensions.

Different tarballs include some subsets of extensions and have versioning which helps you upgrade choosing the right one for your MediaWiki core release.

Extension Distributor works well for most people who want a snapshot of extensions that will work with their supported versions of MediaWiki.

If you want a lot of extensions then downloading from Git is probably best. If you don't have Git but you want to upgrade a lot of extensions, you might consider using mwExtUpgrader.

Deine LocalSettings.php anpassen

If you use the same LocalSettings.php from the old version, you may need to adapt it to how new versions handle it:

Skin registration

Since MediaWiki 1.24, bundled skins like Vector, Monobook, Modern and CologneBlue are no longer part of MediaWiki core, and they need to be registered explicitly in LocalSettings.php to use them, otherwise MediaWiki will warn that you don't have installed skins.

This is what you need to add to LocalSettings.php when upgrading from versions older than 1.24 and want to have available one of those skins:

Extensions are being adapted to use the new extension registration system.
Extensions that are not adapted should use the old way of installing them.
Refer to the installation instructions on the extension's page for more information.

Das Update-Skript ausführen

You can upgrade the MediaWiki database in two ways: Either from the command line or from the web browser. If you have shell access to your server, upgrading from the command line is recommended, since this reduces the risk of the upgrade process being interrupted by a timeout or connection reset.

Kommandozeile

Access the command line of your server or an SSH shell or similar. You can access the command line by connecting to your server via SSH. If the local PC you are working on runs Microsoft Windows, you will need a tool like PuTTY to use SSH. From the command line or the Shell, change to the maintenance directory and execute the update script:

$ php update.php

On a Linux server if you get an error try performing the same command as root (sudo php maintenance/update.php). Note for simple installations on Windows (e.g. with XAMPP):
First make sure that your web server (such as Apache) and your database (such as MySQL) are running.
Then run update.php: right-click it, select Open With, and browse to PHP.exe.
The resulting command prompt window will likely autoclose when the schema upgrade completes.

You might see a message that your PHP version is too old and that MediaWiki needs a newer version. After that message the update aborts. Reason for this error is that the command line can use another PHP version than that one which you have when you execute MediaWiki from the web server. When you get this message you should check, if you can execute a newer PHP version on the shell by using a different command: That might e.g. be php5 or php56. If another version is available and - if so - under which name, depends on the setup of your server. If it does not work, ask your hoster; he will surely know.

MediaWiki will inspect the existing schema and update it to work with the new code, adding tables and columns as needed.

If you use a Shared database, you should pass the --doshared parameter if you want the shared tables to be updated. Otherwise they won't be touched by the update script.

What to do in case of "ALTER command denied to user" error (or similar)

In case the scripts abort with a message similar to:

Error: 1142 ALTER command denied to user 'wiki'@'localhost' for table 'mytable' (localhost)
ERROR: must be the owner of the mytable relation

In some cases, an old $wgDBmwschema variable (for Postgres) seems to be read for the table name to update instead of $wgDBname, even when mysql is used. If this is the case, just get rid of the $wgDBmwschema definition in LocalSettings.php.

What to do in case of "unexpected T_STRING" error

Individuals running update.php from the command line may encounter the following error:

syntax error, unexpected T_STRING, expecting T_OLD_FUNCTION or T_FUNCTION or T_VAR or '}' \
in ~/maintenance/commandLine.inc on line 13

Dieser Fehler tritt auf, wenn update.php unter php4 ausgeführt wird.

Individuals who have their site hosted by providers who provide both php4 and php5 should take the following steps:

from the command line, enter the command 'whereis php5'

once you have discerned the location of the php5 path, list the contents of php5/bin directory

once you've determined the name of the php executable (either php or php5), type in the entire path to execute update.php

Web-Browser

If your database is already big and in high production usage, then you should not be using the Web updater, e.g. because the update process will time out when the maximum_execution_time is reached. In that case you should use update.php from the command-line interface (not from the web). What exactly is "too big" depends on your server (e.g. on its performance, the load and on how long the maximum execution time of PHP allows the script to run). If your wiki is too big for the web updater and your hosting provider does not allow command-line access, then you need to migrate your wiki to another hosting account, preferably to one that does have shell access.

Navigate your webbrowser to /mw-config/. For example, if your wiki is at http://example.org/w/index.php, then navigate to http://example.org/w/mw-config/.

Select your language and click continue.

The existing installation should be detected. Follow the instructions on the screen to upgrade it.If asked for the "upgrade key", open your LocalSettings.php file and look for the key assigned to $wgUpgradeKey.

It might happen that the web-updater does not seem to work: Instead of seeing the initial language selection screen, you might see an empty wiki page, possibly with some error message. In this case it is most likely that your webserver uses Rewrite Rules (most likely for short URLs), which do not show you the updater at mw-config/, but a wiki page at Mw-config/, with capital "M". In this case, rename the .htaccess file for the time of the update. Then you should be able to access the web-updater.

Warnung:

If you use this method, make sure to change the name of the .htaccess file back after running the upgrade script! Otherwise short URLs and possibly other stuff will be broken!

Häufig gestellte Fragen

Wie schwierig ist es zu aktualisieren?

If the only file you have modified is LocalSettings.php, and you are upgrading from 1.5 or later, the process is very simple. The amount of human work involved is only a few minutes. The database schema changes will take an amount of time proportional to the size of your database — potentially hours for wikis with millions of pages, but for a more typical size of a few thousand pages, it is usually done in seconds.

Minor upgrades, within the same major version, say from 1.13.0 to 1.13.1, do not require any schema changes at all. You can just update the files. The database needs no update, hence it is not necessary to run the installer script.

Upgrading from 1.4 or earlier is potentially complicated because support for character sets other than UTF-8 was dropped, and the schema for storing bulk text changed. Please read the relevant section in the UPGRADE file.

Upgrading becomes difficult if you have modified our source code, and you don't want your changes to be overwritten. Tools such as diff, patch, Meld or WinMerge may be useful. There is also potential for trouble if you are using unmaintained extensions. Upgrade your extensions at the same time as you upgrade MediaWiki.

If you have modified the skin or use a custom skin you very likely will have to adjust it to work again with the new version of MediaWiki.

Hinweis: Instead of patching your "global" css and js (javascript) files everytime you can simply add the code to your MediaWiki:Common.js and MediaWiki:Common.css pages. As these are part of the database which will be reused when you upgrade, you will not have to patch the MediaWiki core files any more.

How do I upgrade from a really old version? In one step, or in several steps?

It depends: If you are upgrading from MediaWiki 1.4 or older, you should upgrade to MediaWiki 1.5 first. If you are upgrading from a Latin-1 wiki, use upgrade1_5.php (found in MediaWiki 1.5) to convert the relevant parts of the database to UTF-8 ($wgUseLatin1 needs to be set to true in your LocalSettings.php for this to work). Next, run update.php, and then set the $wgLegacyEncoding option in LocalSettings.php to the encoding previously used by the wiki (e.g. windows-1252). This is basically how Wikipedia and other Wikimedia Foundation sites were upgraded from MediaWiki 1.4 to 1.5 – see the relevant settings file (warning: huge page!) and some related notes at Wikitech. You may need to upgrade to MediaWiki 1.4 before running the upgrade1.5 script.
If you want to make a database dump (e.g. MySQL) of your Latin-1 wiki, make sure the type of the old_text field in the text table is mediumblob, not mediumtext, to avoid character encoding issues.

If you are upgrading from MediaWiki 1.5 or newer, you can upgrade in one step, from your old version to the latest stable version. The vast majority of reports, as well as automated testing, indicate that doing it in one step works just fine. If you have trouble believing this, read this mailing list post. However, please note that when you update from old versions, chances that you will encounter PHP errors are bigger than when you upgrade from the version directly previous to the new version. You would have received these errors anyway, also if you had not skipped versions, but if you had each time done each single update. Only will you - when you skipped versions - get them all at the same time. This will make the upgrade more difficult, but do not forget that you did not have the trouble updating to the intermediate versions, which you skipped!

Sollte ich zuerst ein Backup vornehmen?

An upgrade failure may leave your database in an inconsistent state, in between two versions. A PHP or MySQL error might happen during upgrade leaving your database partly upgraded. In such situations it may be possible to somehow fix this problem with much manual work. However, it will be way easier to just put a database backup from before running update.php in place and to continue with that. Otherwise you might have hours of - needless - work.

Recovery is often complex. Volunteers on the support forums are unlikely to be impressed if you neglect to make a backup and then need help to recover from upgrade-related corruption. A better outcome is if you can revert to your backup, and then report the bug against the corresponding MediaWiki project in the upgrade process which caused the corruption.

Kann ich meine LocalSettings.php behalten?

Yes, but you may have to make some minor changes. The format of LocalSettings.php is largely backwards compatible. Changes which break LocalSettings.php compatibility will be documented in the "configuration changes" section of the release notes.

Can my wiki stay online while it is upgrading?

If you are upgrading between minor releases of MediaWiki, all you need to do is update the source files.

Note: the following assumes you have command line access. If you are upgrading between major releases of MediaWiki, the preferred procedure is as follows:

Unpack the new version of MediaWiki into a new directory

Prepare that new directory: copy your current LocalSettings.php from the old directory, copy any installed extensions and custom skins (if any). Check $wgLogo setting in LocalSettings.php and if necessary copy logo file from the old directory to the new directory.

In the release notes for the new version, see if any changes need to be made to LocalSettings.php.

Place the database in read-only mode by inserting the following variable into LocalSettings.php in the old directory - users will see this message if they attempt an edit during the upgrade process:$wgReadOnly = 'Upgrading to MediaWiki 1.32.0';

This no longer works since MediaWiki 1.27, which also prevents running the update script. A workaround for versions since MediaWiki 1.27 can be found in Handbuch:$wgReadOnly. See also task T151833.

New major releases come with new features, which you might want to use: see the release notes for details. In case you need additional arguments to convince your bosses to let you upgrade from a pretty old version, here is a summary: